The invention relates to an arrangement used for filtering out the conveying air when supplying fiber material, for example cotton and the like, to a processing machine provided with an essentially vertical filling chute for the fiber material. A pneumatic fiber feed is assigned to the upper intake opening of the chute while a flocculation device, having a draw-in roll and a fast rotating opening roll, is assigned to the lower discharge opening. The processing machine is further provided with at least one air-permeable surface for filtering out (separating out) the fiber material from the conveying air stream and a device for evacuating the conveying air stream, wherein the conveying air stream is conducted along the opening roll.
In a known arrangement of this type, as shown in German Patent Document No. DE-OS 32 17 668, the total conveying air stream flows along the opening roll and into a downstream installed floccule chute with air-permeable wall surfaces. The conveying air stream is separated from the fiber floccules and is then evacuated while the fiber floccules are conveyed further with the aid of a roll. The conveying air stream is used for condensing the fiber floccules deposited in the floccule chute. In practical operations, the disadvantage of this method is that the air stream conveying the fiber floccules to the upper reserve chute fluctuates, so that the filtered out conveying air stream also fluctuates to a considerable degree.